Well, there is a problem. Zones. These are hard-wired to hex co-ordinates and to some extent base (location) slot numbers. So you can't fundamentally prevent the existence of malaria in the western area for example. Or make more of the map cold e.g. for the Russian front. Weather is zone dependent too.
That's to say nothing of how well the engine would work in other theatres. 60 miles per hex is too big for the Med and it would make European land war ridiculous. As would the silly rail lines.
Shame. I suppose you might be able to hex-edit the zone co-ords but finding the particular bytes in question would be a nightmare.
Still, I bet some one tries eventually






